Life after Climategate

Penn State climate scientist Michael Mann focuses on the politics as well as the science behind global warming.

If anyone thinks that climate scientist Michael Mann has been cowed by last year's controversy over stolen e-mails, known as Climategate ... or by last week's election, which could lead to congressional hearings that target Mann and his colleagues ... well, think again.

"They can threaten whatever they want," the Penn State professor told me on Sunday, after his talk at the New Horizons in Science meeting at Yale University. "I'm quite confident to fight those sorts of witch-hunt attempts."

Although Mann didn't exactly say "Bring it on," he did note that "those on the other side of the aisle will see this as an opportunity." He doesn't think scientists will be pushed on the defensive by their congressional critics.

"We should look at this as an opportunity for offense," he said.

What's all the fuss about?Those House Republicans, as well as Virginia Attorney General Ken Cuccinelli, may be anxious to expose the "climate hoax." But the way Mann sees it, there's not much question that greenhouse-gas levels are going up, that global average temperatures are rising, and that industrial activity is playing a role in that rise. "You might not gather that from the nature of the discourse today," he admitted.

At the same time, he acknowledged that there have been uncertainties in the data, as well as missteps in the way those data have been presented.

For example, one study that became the focus of the Climategate e-mail debate used tree-ring measurements as a proxy for temperatures up to 1960, but switched to a different data set after that point. Mann said that the tree-ring data stopped reflecting true temperatures 50 years ago for reasons that are not yet fully known -- but he added that it was a mistake not to show the data anyway. "That was bad," he said. (A British inquiry into Climategate criticized the "misleading" portrayal of tree-ring data as one of the few scientific lapses in the scientists' conduct. One of the researchers said in an e-mail that he picked up the tree-ring "trick" from Mann.)

The uncertainties have more to do with exactly how hot things will get if current trends continue, rather than whether or not global temperatures will heat up. Mann said it's not known just how much of a positive feedback effect a warmer, moister atmosphere and the increased cloud cover might have -- which is why projections for the global temperature rise by 2100 vary by several degrees. Also, it remains to be seen how well scientists are modeling the effect of weather patterns such as El Nino and La Nina. If the models are off, "maybe we can't trust what they're predicting" when it comes to climate change on a region-by-region level.

But under any scenario, the models point to "an array of potentially deleterious effects" that will accompany rising global temperatures, ranging from stronger storms to the loss of polar ice sheets.

"The ice sheets are not Republican or Democrat," Mann said. "They don't have a political agenda as they disappear."

During his talk, Mann flashed a picture of his daughter and a polar bear at a zoo. "I can't imagine having to tell my daughter when she's grown up that polar bears became extinct ... because we didn't act soon enough to combat a problem that we knew was real, but we couldn't convince the public because we faced so much opposition from a very well-funded, very well-organized effort to distract the public," Mann said.

What is to be done?Mann said scientists "can do our best to call out the disinformation where we see it." One example of this was how Mann reacted to a Climategate op-ed written by former GOP vice-presidential nominee Sarah Palin for The Washington Post. He persuaded the Post to publish his own op-ed, responding to Palin's claims.

Mann praised the American Geophysical Union for providing resources to help set the record straight on climate science. He said journalists also should exercise their traditional role as a "critical and independent arbiter" of the policy debate, particularly in the midst of "politically motivated inquiries that we haven't seen in this country since the 1950s."

It might sound as if Mann relishes the fight, but he acknowledged that life after Climategate has not been easy for him. His routine now includes dealing with veiled death threats as well as investigations such as the one in Virginia. (The University of Virginia has reportedly run up a legal tab totaling $350,000 to fend off the state attorney general.) Mann is doing less research, and more speaking and writing. (For example, he's one of the scientists behind the RealClimate blog.)

"I spend quite a bit of time these days on what I might generously describe as outreach," he told me. "I think not every scientist should be doing this -- but more scientists should."

Update for 12:10 a.m. ET Nov. 9: During his talk, Mann praised the AGU for its role in the climate change debate, but some of that praise may have been based on reports about a campaign against global warming skeptics -- reports that the AGU later said were "inaccurate." In my report, I've revised the reference to the AGU role to reflect what the AGU says that role actually is.